检索结果-南通市图书馆

Van der Waals contacted WSe_(2) ambipolar transistor for in-sensor computing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2023年第11期16卷 12713-12719页

作者： Yue Wang haoran Sun Zhe sheng Jianguo Dong Wennan Hu Dongsheng Tang Zengxing Zhang School of Microelectronics Fudan UniversityShanghai 200433China Synergetic Innovation Center for Quantum Effects and Application Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of EducationSchool of Physics and ElectronicsHunan Normal UniversityChangsha 410081China National Integrated Circuit Innovation Center No.825 Zhangheng RoadShanghai 201203China

Image sensors with an in-sensor computing architecture have shown great potential in meeting the energy-efficient requirements of emergent data-intensive applications,where images are processed within the photodiode arrays.It demands the composed photodiodes are reconfigurable,which are usually achieved by ambipolar two-dimensional(2D)semiconductors.To improve the ambipolar charges injection,here we report a top-gated field-effect transistor(FET)design that is of bottom van der Waals contact via transferring ambipolar 2D WSe_(2) onto Pd/Cr source/drain electrodes.The devices exhibit nearly negligible effective barrier heights for both holes and electrons based on thermionic emission mode,and show an almost balanced on/off ratio in the p-branch and n-branch.By replacing the top gate with two aligned semi-gates,the devices can effectively function as reconfigurable photodiodes.They can be switched between PIN and NIP configurations via controlling the two semi-gates,exhibiting good linearity in terms of short-circuit current(ISC)and incident light power density.The photodiode arrays are also demonstrated for in-sensor optoelectronic convolutional image processing,showing significant potential for in-sensor computing image processors.

关键词： ambipolar transistor van der Waals contact reconfigurable photodiode in-senor computing

Insights into the influence of temperature on the adsorption behavior of sodium oleate and its response to flotation of quartz

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2022年第2期32卷 399-409页

作者： Shaohang Cao Wanzhong Yin Bin Yang Zhanglei Zhu haoran Sun Qiuyue sheng Keqiang Chen School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’an 710054China

Temperature affects the flotation of quartz in the calcium/sodium oleate(Na OL)system,while there is a lack of understanding of its potential mechanism.Therefore,in this work,the flotation response of quartz to temperature was investigated via micro-flotation experiments,interface property analyses,and theoretical calculations.Flotation results demonstrated that increasing temperature contributed to higher flotation recovery of quartz,which enhanced the removal of quartz from hematite.Surface tension results revealed that higher temperatures lowered the critical micelle concentration(CMC)and surface tension of the Na OL solution,and thus enhanced its surface activity.Solution chemistry calculations and X-ray photoelectron spectroscopy(XPS)measurements confirmed that the increased content of Ca(OH)+achieved by increasing temperatures enhanced the adsorption amounts of calcium species(acting as activation sites)on the quartz surface.Dynamic light scattering(DLS)measurements verified that the association degree of RCOOàto form(RCOO)22àwas strengthened.Furthermore,adsorption density measurements and molecular dynamics(MD)simulations confirmed that increasing the temperature facilitated Na OL adsorption toward the surface of the quartz,which was attributed to the stronger interaction between Na OL and the calcium-activated quartz surface at higher temperatures.As a result,quartz flotation was improved by increasing temperatures.Accordingly,a possible adsorption model was proposed.

关键词： Temperature Quartz flotation Calcium Sodium oleate Adsorption features Molecular dynamics simulation

Coverage enhancement for 6G satellite-terrestrial integrated networks: performance metrics, constellation configuration and resource allocation

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第3期66卷 40-59页

作者： Min sheng Di ZHOU Weigang BAI Junyu LIU haoran LI Yan SHI Jiandong LI State Key Laboratory of Integrated Service Networks Xidian University Department of Broadband Communication Peng Cheng Laboratory

Since the base station-centric wireless coverage mode of 5G is difficult to support future stereoscopic global wireless coverage demands, the future infrastructure of 6G satellite-terrestrial integrated network(STIN) with mega constellations will extend from the terrestrial network to the integrated satellite-terrestrial architecture, so as to realize the improvement of wireless coverage capability through extending the spatial and temporal coverage. However, what are the specific quantitative indicators of wireless coverage? What is the basis for the effect of network configuration with mega constellations on coverage performance? How to form non-uniform coverage through intelligent resource scheduling to match non-uniformly distributed service requirements in the future 6G STIN? The aforementioned unknown fundamental problems have become a bottleneck restricting the further development of coverage expansion in the future 6G STIN. In this paper,we start with the evolution route of wireless coverage and the vision of 6G coverage and propose coverage performance evaluation metrics in 6G STINs from the perspective of signal coverage, capacity coverage, and service coverage. Furthermore, we investigate the relationship between coverage structure and coverage capability in 6G STINs with mega constellations and we find network structure characteristics suitable for 6G non-uniform service requirements, thus guiding constellation design in 6G STINs by analyzing and comparing the coverage performance of several typical mega constellations. Afterwards, we explore the application of artificial intelligence in resource collaboration to provide technology reference to enhance coverage capability for dynamic 6G service demands. Finally, we analyze possible technical challenges for improving service coverage performance in 6G STINs to provide researchers with new ideas.

关键词： 6G satellite-terrestrial integrated networks on-demand wireless coverage performance metrics constellation configuration intelligent resource scheduling

Unveiling annealing texture formation and static recrystallization kinetics of hot-rolled Mg-Al-Zn-Mn-Ca alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第8期36卷 104-118页

作者： Qinghang Wang Bin Jiang Aitao Tang Jie Fu Zhongtao Jiang Haoran Sheng Dingfei Zhang Guangsheng Huang Fusheng Pan State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Academy of Science and Technology Chongqing 401123China Research Institute for New Materials Technology Chongqing University of Arts and SciencesChongqing 402160China Shanghai Aerospace Equipment Manufactory Shanghai 200245China

The development of Mg-Al-Zn-Mn-Ca series alloys provides a potential prospect to achieve high strength and formability at room temperature(RT).The formation of elliptical annular texture is treated as a crucial factor for the enhanced RT formability.However,the origin of such an elliptical annular texture formation has been rarely reported.Herein,we unveiled the formation and evolution of elliptical annular texture in the hot-rolled Mg-1.6 Al-0.8 Zn-0.4 Mn-0.5 Ca(AZMX1100,wt.%)alloy after annealing at different temperatures for 1 h,and its static recrystallization(SRX)kinetics in given annealing temperature for different time.The results revealed that the formation of elliptical annular texture in the hot-rolled AZMX1100 alloy after annealing was derived from nucleation-oriented SRX mechanism,which took place in 200-300°C,induced by cracked chain-shaped Al2 Ca phases,contraction twins,intersections of double twins,intersections of double twins and grain boundaries and non-basal slips.On further annealing from300-450°C,the grains with 45°–70°transverse direction(TD)preferentially grew,which made elliptical annular texture extended along the TD.Based on the Johnson-Mehl-Avrami-Kolmogorov(JMAK)model,Avrami exponent n value was estimated to be 0.68–1.02,attributed to non-random SRX nucleation,giving rise to the lower activation energy QRof nucleation of^74.24 k J/mol.Since the co-segregation of Al,Zn and Ca atoms in grain boundaries created a strong interaction of solutes and grain boundaries,the hot-rolled AZMX1100 alloy exhibited the higher activation energy Qg(~115.48 k J/mol)of grain growth.

关键词： Mg-Al-Zn-Mn-Ca alloy Elliptical annular texture Nucleation Grain growth Static recrystallization kinetics

Two-dimensional complementary gate-programmable PN junctions for reconfigurable rectifier circuit

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第1期16卷 1252-1258页

作者： Zhe sheng Yue Wang Wennan Hu haoran Sun Jianguo Dong Rui Yu David Wei Zhang Peng Zhou Zengxing Zhang State Key Laboratory of ASIC and System School of MicroelectronicsFudan UniversityShanghai 200433China National Integrated Circuit Innovation Center Shanghai 201203China

The unique features of ambipolar two-dimensional materials open up a great opportunity to build gate-programmable devices for reconfigurable circuit applications,e.g.,PN junctions for rectifier circuits.However,current-reported rectifier circuits usually consist of one gate-programmable PN junction as the rectifier and one resistor as the load,which are not conductive to voltage output and large-scale integration.Here we propose an approach of complementary gate-programmable PN junctions to assemble reconfigurable rectifier circuit,which include two symmetric back-to-back black phosphorus(BP)/hexagonal boron nitride(h-BN)/graphene heterostructured semi-gate field-effect transistors(FETs)and perform complementary NP and PN junction like complementary metal-oxide-semiconductor(CMOS)circuit.The investigation exhibits that the circuit can effectively reconfigure the circuit with/without rectifying ability,and can process alternating current(AC)signals with the frequency prior 1 KHz and reconfiguration speed up to 25μs.We also achieve the reconfigurable rectifier circuit memory via complementary semi-floating gate FETs configuration.The complementary configuration here should be of low output impedance and low static power consumption,being beneficial for effective voltage output and large-scale integration.

关键词： two-dimensional(2D)material PN junction rectifier circuit complementary configuration

Influence of minor Ce additions on the microstructure and mechanical properties of Mg-1.0Sn-0.6Ca alloy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第2期37卷 26-37页

作者： Yanfu Chai Chao He Bin Jiang Jie Fu Zhongtao Jiang Qingshan Yang Haoran Sheng Guangsheng Huang Dingfei Zhang Fusheng Pan State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing400044China Chongqing Academy of Science and Technology Chongqing401123China Research Institute for New Materials Technology Chongqing University of Arts and SciencesChongqing402160China School of Metallurgy and Material Engineering Chongqing University of Science and TechnologyChongqing401331China Shanghai Aerospace Equipment Manufactory Shanghai200245China

The microstructure and mechanical properties of Mg-Sn-Ca-Ce alloys with different Ce contents(0.0,0.2,0.5,1.0 wt%)were studied at room temperature.Ce additions to ternary Mg-Sn-Ca alloy resulted in grain refinement as well as a change in the category of second phase from CaMgSn to(Ca,Ce)Mg Sn and Mg12Ce.The volume fraction of second phase increased with rising Ce content,which aggravated the restriction of DRXed grain growth during the extrusion process and eventually led to texture weakening of as-extruded Mg-Sn-Ca based alloys.In terms of plasticity,owing to vigorously activated basal slip and homogeneous distributed tensile strain in tension,the tensile ductility of as-extruded alloys reached the maximum value of 27.6%after adding 0.2 wt%Ce,which enhanced by about 26%than that of ternary MgSn-Ca alloy.However,further Ce additions(0.5 and 1.0 wt%)would coarsen the second phase particles and then impair ductility.The tension-compression yield asymmetry of as-extruded Mg-Sn-Ca ternary alloy was alleviated greatly via Ce additions,due to the joint effects of grain refinement,increased amount of strip distributed second phase particles and texture weakening.

关键词： Mg-Sn-Ca alloy Ce content Microstructure Texture Mechanical properties

在线全文

学校读者我要写书评

暂无评论

地方高等学校专项招收农村学生的现状与优化

教育研究 2023年第2期44卷 101-111页

作者：崔盛田浩然中国人民大学教育学院北京100872

扩大高等教育的机会供给,特别是增加优质高等教育的入学机会,是世界各国为促进高等教育机会公平,普遍且优先采用的举措。对此,我国先后实施了国家专项计划、高校专项计划和地方专项计划,构建了重点大学面向农村和贫困地区倾斜招生的公... 详细信息

扩大高等教育的机会供给,特别是增加优质高等教育的入学机会,是世界各国为促进高等教育机会公平,普遍且优先采用的举措。对此,我国先后实施了国家专项计划、高校专项计划和地方专项计划,构建了重点大学面向农村和贫困地区倾斜招生的公平性政策体系。伴随我国进入脱贫攻坚成果巩固阶段、户籍制度深化改革、高等教育普及化和乡村振兴战略实施等宏观形势发展,原有专项计划政策体系面临着招生标准模糊、政策公平成效拓展乏力、与脱贫和农村地区发展衔接不足等问题。与国家专项计划、高校专项计划的定位、招生标准有所不同,地方专项计划由各地自主调控并制定方案,招生面向省内,对应分数段的学生规模更大,能够发挥更显著的倾斜作用。面对新的形势,地方专项计划应从公平出发,根据不同省份的政策供需情况,兼顾地方发展效率,向下放权“做足差异”,并在各省份扩展实施区域、增列承担高等学校过程中,更好地衔接本地社会经济发展需求,推动专项计划政策体系整体完善和普惠化发展。

关键词：地方专项计划农村学生高考招生政策乡村振兴高等教育公平

“人才增量扩充”还是“资源存量优势”——研究生教育规模影响高科技创新的实证研究

在线全文

学校读者我要写书评

暂无评论

研究生教育研究 2022年第6期 22-30,76页

作者：崔盛田浩然中国人民大学教育学院北京100872

研究生教育支撑高科技创新不仅体现在通过人才培养,扩充高级人力资本增量的方面,还包括依托自身“产教学研”资源的存量优势,从而释放出的强大科技创新效能。利用我国2003-2017年的省级面板数据,分析了研究生教育规模对高科技创新的影响... 详细信息

研究生教育支撑高科技创新不仅体现在通过人才培养,扩充高级人力资本增量的方面,还包括依托自身“产教学研”资源的存量优势,从而释放出的强大科技创新效能。利用我国2003-2017年的省级面板数据,分析了研究生教育规模对高科技创新的影响,结果发现:①研究生教育规模对总的科创成果数呈现抑制效果,表明科创成果的“数量扩张”与“质量升级”之间可能存在一定的取舍关系;但是对高科技创新成果数的正效应显著,表明研究生教育对科技创新的支撑作用主要集中在高技术领域;②区域扩充的研究生“人才增量”与保有的研究生教育“资源存量”对高科技创新具有联合促进效应;③在研究生教育发展特征不同的省份之间研究生教育支撑高科技创新的效果存在差异,优质人才增量扩充对于释放物质资本效率、稳固资源存量优势等的意义重大。

关键词：研究生教育规模人才增量资源存量高科技创新

Comparison of microstructures and mechanical properties of composite extruded AZ31 sheets

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2019年第4期7卷 547-554页

作者： Yanfu Chai Yan Song Bin Jiang Jie Fu Zhongtao Jiang Qingshan Yang Haoran Sheng Guangsheng Huang Dingfei Zhang Fusheng Pan State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Chongqing Academy of Science and Technology Chongqing 401123China Research Institute for New Materials Technology Chongqing University of Arts and SciencesChongqing 402160China Shanghai Aerospace Equipment Manufactory Shanghai 200245China

The microstructures and mechanical properties of the composite extruded AZ31/AZ31 and AZ31/4047 Al sheets were investigated and made a comparison to the conventional extruded AZ31 sheet.Owing to the introduced intense shear deformation at the interface during the composite extrusion,grain refinement and tilted texture were detected in AZ31 layers of the AZ31/AZ31 and AZ31/4047 Al sheets,while the conventional extruded AZ31 sheet exhibited a relative coarse,inhomogeneous microstructure and strong basal texture.The compressiontension yield ratio was increased gradually from the AZ31 to the AZ31/AZ31 and AZ31/4047 Al sheets.Besides,the AZ31/4047 Al sheet could successfully accomplish the whole bending forming process at room temperature,while the AZ31 and AZ31/AZ31 sheets were both bend-formed to failure with significant cracks in the outer tensile region under the identical bending parameters.Moreover,under the same bending strain,both the outward offset degree of strain neutral layer and the sheet thickening were more serious in the AZ31/4047 Al composite sheet than those of the AZ31 and AZ31/AZ31 sheets.The foremost reason was the quite wide gap of material properties between Mg alloy AZ31 layer(tensile loading in the outer region)and Al 4047 layer(compressive loading in the inner region).

关键词： Mg alloy sheet Composite extrusion Tension-compression yield asymmetry Bendability